"Our research of Indian smartphone buyers revealed major pain points of battery, camera and storage, etc. We developed the 'Billion Capture+' keeping these in mind," said Hrishikesh Thite, Category Head, Billion, in a statement.

The smartphone comes with a 3,500mAh battery and "quick charge" technology that, the company claimed, would provide seven hours of battery life with 15 minutes of charge.

The phone runs Android Nougat operating system (OS), sports a metal body and a fingerprint sensor on the rear and will offer unlimited cloud storage.

"The features in the 'Capture+' too have been derived from deep data-mining of millions of Flipkart customers' reviews. We're sure this customer-centricity will delight Indian smartphone buyers," said Sachin Bansal, Co-Founder and Executive Chairman, Flipkart.

The smartphone will retail in "Mystic Black" and "Desert Gold" colours.

Twitter has warned of "unusual activity" from state-sponsored actors based in China and Saudi Arabia after it found a bug that could have revealed the country code of users' phone numbers or if their account was locked.